1. Field of the Invention
This invention relates to a method and apparatus for manufacturing a semiconductor device by using lamps to heat a wafer having semiconductor devices thereon.
2. Background Art
In an apparatus for manufacturing a semiconductor device by using lamps to heat a wafer having semiconductor devices thereon, the lamps are placed at the backside of the wafer where the semiconductor devices are not located. At the frontside of the wafer, radiation thermometers are placed for measuring radiation emitted from the wafer (see, e.g., JP2001-274109A). The radiation intensity of radiation emitted from the wafer is measured by the radiation thermometers, and the temperature of the wafer is determined from the radiation intensity. Electric power supplied to the lamps is adjusted on the basis of this wafer temperature.
However, despite using radiation thermometers, the emissivity may be nonuniform within the wafer, or within the region including the wafer where the heating temperature should be uniform. In these cases, the temperature within the wafer becomes nonuniform, and the resulting semiconductor devices may have nonuniform characteristics within the wafer, thereby becoming a cause of decreased semiconductor device yields.